shared/crypto: Transform bt_cryto in a singleton

This makes bt_crypto always return the same instance thus avoiding the
problem of having multiple PF sockets opened which may hit the file
descriptor limit.

Signed-off-by: Anuj Jain <anuj01.jain@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>

diff --git a/src/shared/crypto.c b/src/shared/crypto.c
index 378bb61..8afdbf4 100755 (executable)
--- a/src/shared/crypto.c
+++ b/src/shared/crypto.c
@@ -126,34 +126,40 @@ static int cmac_aes_setup(void)
        return fd;
 }
 
+static struct bt_crypto *singleton;
+
 struct bt_crypto *bt_crypto_new(void)
 {
-       struct bt_crypto *crypto;
+       if (singleton)
+               return bt_crypto_ref(singleton);
 
-       crypto = new0(struct bt_crypto, 1);
+       singleton = new0(struct bt_crypto, 1);
 
-       crypto->ecb_aes = ecb_aes_setup();
-       if (crypto->ecb_aes < 0) {
-               free(crypto);
+       singleton->ecb_aes = ecb_aes_setup();
+       if (singleton->ecb_aes < 0) {
+               free(singleton);
+               singleton = NULL;
                return NULL;
        }
 
-       crypto->urandom = urandom_setup();
-       if (crypto->urandom < 0) {
-               close(crypto->ecb_aes);
-               free(crypto);
+       singleton->urandom = urandom_setup();
+       if (singleton->urandom < 0) {
+               close(singleton->ecb_aes);
+               free(singleton);
+               singleton = NULL;
                return NULL;
        }
 
-       crypto->cmac_aes = cmac_aes_setup();
-       if (crypto->cmac_aes < 0) {
-               close(crypto->urandom);
-               close(crypto->ecb_aes);
-               free(crypto);
+       singleton->cmac_aes = cmac_aes_setup();
+       if (singleton->cmac_aes < 0) {
+               close(singleton->urandom);
+               close(singleton->ecb_aes);
+               free(singleton);
+               singleton = NULL;
                return NULL;
        }
 
-       return bt_crypto_ref(crypto);
+       return bt_crypto_ref(singleton);
 }
 
 struct bt_crypto *bt_crypto_ref(struct bt_crypto *crypto)
@@ -179,6 +185,7 @@ void bt_crypto_unref(struct bt_crypto *crypto)
        close(crypto->cmac_aes);
 
        free(crypto);
+       singleton = NULL;
 }
 
 bool bt_crypto_random_bytes(struct bt_crypto *crypto,